Sutra I, 4: When the Self is lost in life's vacillations

At all other times,
the Self
appears
to assume the form
of thought's vacillations
and the True Self
is
lost.

The True Self is like a glass of water.  It's naturally clear and still.

Emotions and judgments color the water, boil it, or thrash it around.

Though it is still water, it is nearly unrecognizable as the pure, sparkling substance that it was originally, but instead recognized as the vacillations that color its qualities.